
from datetime import datetime

if __name__ == '__main__':
    print(f"this is float {0.1:.20f}")

    year = 2022
    print(f"hello {year}")
    # print(f'hello {year=}')
    print(f"hello {year:0<4}")
    print(f"hello {year:.1f}")
    print(f"hello {year:,}")

    now = datetime.now()
    print(f"{now:%Y-%m-%d_%H:%M:%S}")
